Composite materials have been used increasingly in a variety of industries, including the automotive, marine and aerospace industries. Composite materials have been used to produce nonload-carrying structures, such as boat hulls or automobile body panels. Composite materials have also been applied in the manufacture of load-carrying structures, such as pressure vessels and aircraft fuselages.
Composite materials especially have application in the design of structural members carrying tensile loads. Composite materials used in these designs include strong fibrous materials, such as carbon, aramid, glass or quartz, bonded together with a resin material, such as an epoxy. Such materials can have the advantage of a high tensile strength to weight ratio, permitting the design of lightweight structures having substantial strength in tension. Since the load in these materials is carried primarily by the fibers, a variety of composite materials have been developed with unidirectional fibers, that is, the fibers are substantially aligned in a uniform direction. Thus, these materials are frequently used in designs that place the fibers along the direction of the tensile load in a structural member.
However, the composite material designs can have the disadvantage that the unidirectional fibers do not follow the contour of the structural member. For example, in a structural element that includes a surface that is curved within a plane, the composite material can be trimmed to the shape of the planar arc, but the fibers do not follow the curve of the arc. In such a design, the orientation of the unidirectional fibers does not lie in the direction of loading in the structural member. Furthermore, the unidirectional fibers are severed along the trimmed edge of the curve.
Accordingly, it is desirable to provide a method of manufacturing curved composite structural elements with load-bearing fibers aligned along the curvature of the structural element.